This application claims the priority of German patent 198 30 762.4, filed Jul. 9, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a device for fastening a working part, especially an axle, to a beam in the body of a motor vehicle, consisting of a stud with internal screw thread disposed on a beam by means of a flange, and of a screw on the working part, which cooperates with this stud.
It is known to mount the control arm for the arrangement of the links for the wheels of a motor vehicle and for the arrangement of the shaft driving the wheels and differential on each longitudinal beam of the body by means of a fastening point that is "loose" for equalization of tolerances and with a rigid fastening point. For the rigid fastening the former practice has been to weld internally threaded studs to the bottom of the lower flange of the channel-shaped beam with a flange. The MIG or MAG welding processes used for this welding are complicated.
A device for forming a "loose" fastening is disclosed in German patent document DE 195 33 138 C1. In that case a hood-like sheet metal cage is disposed on a flat metal part of the body, which in turn is provided with a disk-like holder for the threaded socket which is provided either with a threaded stud which is guided with radial clearance in the hood-like sheet metal cage, or which has an annular groove to receive an annular margin of the threaded socket which in turn is disposed for radial displacement in the mounting. With this measure the threaded socket remains radially displaceable in all directions in front of the opening provided in the body through which the screw is then passed to install the working part. Equalization of tolerances is possible in all directions.
French patent document FR 2 694 226 A1 discloses the fixation of nuts for mounting bolts serving for mounting an axle in a certain position by means of a jig, and then welding it. Such threaded sockets must, as in the case of the types of construction mentioned above, be welded with difficulty in order to achieve the necessary stability.
Through German patent document DE 43 14 441 C1 it is known to apply reinforcing parts with a threaded bore for fastening a motor vehicle assembly to a hollow beam with at least two flanges on two sides of the hollow beam and to provide for spot welding. The threaded bore itself is configured as a material passage and positioned with the free end at a bore in the hollow beam. By this configuration the forces that act are said to be distributed uniformly and over a broad surface. A threaded insert which is displaceable to a certain extent for alignment purposes is not, however, contemplated.
It is the object of the present invention to provide a simpler construction of the rigid fastening point of a working part of the kind generally described above.
This and other objects have been achieved according to the present invention by providing a threaded socket which is introduced with clearance into an opening in the bottom flange of the beam and having a flange which is placed against the beam surface surrounding the opening, and which is affixed to a cage serving as a support which is provided with surfaces in contact with the flange and with the upper and lower flanges of the beam. This design, which can be achieved in an especially simple manner on a beam of channel-like construction, which is provided in one of its flanges with an opening to accommodate the bolt, has the advantage that complex welding of the flange to the beam is unnecessary and instead a simple spot welding of the cage to the upper and lower beam flange and a spot welding of the flange to the cage is sufficient to achieve an extraordinarily stable arrangement. The cage serving for the fixation of the threaded stud is carried with sufficient stability in the beam and secures and in turn holds the flange with the threaded stud on the beam. Accordingly a simple possibility for adjustment is created prior to the spot welding.
In a further embodiment of the invention the stud flange can in turn be spot welded to the bottom flange and provided with at least two upstanding guiding walls aligned parallel to one another for contact with contact surfaces of the cage, which is thus easily mounted and held on the beam. In a further embodiment of the invention, the cage may comprise of two lateral walls running parallel to one another at least in the range of the guiding walls of the flange, which are matched to the height of the beam and are provided at their extremities with flanges running parallel to the beam flanges for fastening to the beam.
These lateral walls can be connected together by at least two cross walls for purposes of stability, the front cross wall of the cage at the open side of the beam being so dimensioned that the guiding walls of the flange fit beneath it to make the installation possible.
Lastly, in a further embodiment of the invention, it can be arranged for the upwardly reaching guiding walls of the flange to be the prolongation of opposite lateral walls of a lateral wall frame around the flange. With this configuration an especially stable construction and good mounting can be achieved in the cage.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.